Control device for burner nozzles



July 13, 1943- o. c. TAPER ETAL CONTRQL DEVICE FOR BURNER NQ'ZZl- ES Original Filed Sept. '7, 1939 2 Sheets-Sheet 1 :5 ATTORNEA;

July 13, 1943; b. c. TAPER EI'AL' CONTROL DEVICE FQR BURNER NOZZLES Original Filgql sew. 7, 193 s 2 Sheets-Sheet 2 INVENTORS OSCAR C, TAPE]? BY JOHN G1. FROST M f ATTORNEYS Patented July 13, 1943 UNITED STATES PATENT OFFICE CONTROL DEVICE FOR BURNER NOZZLES Oscar C. Taper and John G. Frost, Seattle, Wash, assignors to Ray Oil Burner 00., San Francisco, Calif., a corporation of Delaware 11 Claims. (C1. 1371'53) Our oil burner may be applied to any acceptable type of furnace and is characterized by being provided with means for heating the heavier and cheaper fuel oils so that they can be properly atomized and burned in the smaller types of domestic furnaces. To accomplish this purpose we provide a water heating unit which, preferably, maintains the oil passing into the burner at sufficiently high temperatures so that it will flow and atomize freely, yet by the use of this water heating means the temperature can be maintained within very close limits so that there is no danger of forming gas or partially cracking the oil or carbonizing such as might be encountered if the oil came into contact with a high temperature electric heating element.

When the heavier oils are raised to a proper working temperature they function very similarly to the lighter fuel oils, normally referred to as Diesel oils, and the normal working parts of the ordinary Diesel oil burner are employed in our arrangement, such as the fuel pump, the fan to produce a blast of air under pressure, and the usual electrical ignition means which assures proper ignition and the maintenance of it.

It is an absolute necessity in burning the heavier fuel oils in a domestic plant to have means for controlling the supply of fuel according to the pressures applied to the fuel, which means will also retract the fuel oil from the burner nozzle or tip so that there is no possibility of it congealing in the tip during the off periods of the furnace. In this way, according to the practice taught by our application for Domestic fuel oil burners, Ser. No. 293,830, filed September 7, 1939, which matured into Patent No. 2,248,395, granted July 8, 1941, and of which this application is a division, the fuel is withdrawn from the nozzle tip into the heating coil where during the next on period of the furnace it will be raised to the proper temperature necessary for eflicient atomization and burning.

An important object of our present invention is to provide means for withdrawing the oil from the supply line adjacent the burner tip to the end that there will be no drip from the nozzle when it shuts off and, secondly, that the oil will be withdrawn fully into the water heating chamber so that it will be maintained in proper condition for the next use of the burner or, if the burner is to be shut off for some time, the oil will be in condition so that it will be properly reconditioned before it is again supplied to the burner tip.

A further object of our present inventionis to provide a permanent air vent for the oil pump.

A further object is to provide means whereby if oil, of lower viscosity and flash point than is normally used with the burner, is supplied, the same will be bi-passed back into tank without going through the heating coils, or it being possible for the same to be passed through the burner tip.

Another object of our invention is to provide means whereby the oil is shut off to the nozzle, when the burner shuts down, while still under full atomizing pressure.

A further object is to provide means for causing a reverse circulation of oil through the small strainers that are employed to remove impurities from the oil before it is discharged to the burner tip, this reversible flow tending to loosen up any materials that may have become lodged on the fine meshed screen.

Other and more specific objects will be apparent from the following description taken in connection with the accompanying drawings, wherein Figure 1 is a top plan view of our burner with the furnace Walls shown in dashed lines.

Figure 2 is a side elevation of portions in section showing the general arrangement of the essential parts making up our invention.

Figure 3 is an enlarged sectional view of the control device shown in Figure 2.

Figure 4 is a cross-sectional view taken on lines 4-4 of Figure 3.

Figure 5 is a view .partly in section taken along lines 55 of Figure 3.

Figure 6 is a vertical cross-sectional view taken along lines (iii of Figure 3, and

Figure '7 is a vertical, cross-sectional view taken along lines l'l of Figure 3.

Referring to the drawings, throughout which like reference characters indicate like parts, I6 designates the fire or blast tube of our oil burner. This follows more or less conventional structure as does the air fan l8, and the oil pump 2t). As is usual in many types of oil burners, we provide a common electric motor 22 which is directly connected to the rotor of fan 18, and is then connected by means of the speed reducing belt 23 and with fuel pump 20. Inasmuch as the fuel pump in this instance is to handle oil of greater viscosity than the usual Diesel oil burner, the pump is supplied in an increased size and operated at somewhat slower speed than is usual. The fire tube extends through the wall of furnace F as is common with burners of this type.

Our invention resides largely in the control means disposed between the delivery side of the pump and the burner nozzle or tip 24. Disposed by preference below the level of the tip 24 is the water heating compartment 23. This we form in any approved manner, normally by casting the same in the form of a reservoir or chamber which after the showing of Figure 2 is adapted to fit around tube I6 and be secured thereto. The chamber is preferably provided with insulation as 21 and is equipped with the electric heating element 28 and further provides for the oil heating coil 30. This coil should have sufficient turns, or at least sufiicient area so that the flow of oil required by the burner, usually around a gallon and a half or two gallons an hour, will be in the chamber long enough to pick up the full temperature of the water. Also immersed in the water of chamber 26 are two heat control switches 32 and 33; switch 32 is so connected as to close the energizing circuit for a relay which in turn energizes the motor 22. It also closes a circuit for a transformer which supplies the current to the ignition electrodes 38. Switch 33 controls the heating element 28 and in this manner the water temperature within chamber 26 is maintained within the limit found to produce most satisfactory operation. This temperature will vary somewhat with different types of oil. For a fuel oil of gravity 18 Baum this temperature can be satisfactorily maintained between the limits of 1'75 degrees and 190 degrees F. Formed as part of and communicating with chamber 26 is the neck or tube 40 which supports burner nozzle 24. This tube is preferably insulated as illustrated at 42 and supplies a water jacket for the oil supply pipe 44. Tube 46 with its insulation passes through an opening 46 cut in the lower portion of tube 16 after the showing of Figure 2.

For purposes of reference the fluid used in the heater reservoir is spoken of as water for the reason that that fluid is almost universally available for use where such a heater device may be installed. Where these designations appear in the specification and in the claims, it is to be understood that they are not to be considered limitive, for obviously a multitude of fluids if available could be used. N o matter what fluid is used, the device per se would come within the scope of the invention and claims.

Disposed in the oil circuit between chamber 26 and pump is an oil control cylinder 50. This cylinder is provided with a reciprocable piston 52 which is normally drawn to the right as viewed in Figures 2 and 3 by the tension spring 54. This spring is anchored at one end by bolt 55 and is anchored to piston 52 by bolt 56. A small buffer spring is inserted in the ends of cylinder 50 as illustrated at 58.

This spring, the pressure of which can be adjusted by the threaded nut 59, regulates the oil pressure within cylinder 58 by determining the position of piston 52 with respect to port H, thereby indirectly affecting the oil pressure at the nozzle. At one end cylinder 58 is provided with a port 65] through which the line 62 leading from pump 20 discharges the fuel and, at the same time, the same opening provides a by-pass connection for tube 64 which is connected into a return 66 communicating directly with the supply tank.

Part way up toward the opposite end of cylinder 56 is an elongated discharge port 68; this port connects to a chamber housing screen 10 which in turn connects to the fuel pipe 44 in the center of which is formed the heating coil 30.

Disposed further along cylinder 50 is a second port II; this port connects by passageway 12 to the left-hand end of the cylinder and also back to the tank return line 66, there being a ball check valve disposed in the line. It is desirable that port ll be positioned to open after port 68 opens, then on the return of the piston as it moves to the right, port H will be closed before the final closing of port 68.

Method of operation The general functioning of our fuel oil burner, aside from the heating of the oil, is similar to that of a conventional Diesel oil burner so commonly installed for domestic heating. As in the conventional systems, a room thermostat (not shown) is employed which is usually at a predetermined room temperature, and when it is actuated by changes in temperature this effects the closing of a circuit to the two temperature control switches 32 and 33. Thereafter the heating element 28 under control of the switch 33 will immediately start to bring the temperature of the fluid in chamber 26 up to that required for the proper functioning of the device. As soon as this temperature has been obtained the rise in temperature will cause switch 32 to complete its circuit and effect a flow of electrical energy to motor 22 and to the ignition electrodes 38 and the burner will then begin to function. In our arrangement, a warm-up period, it can be seen, is required after the room thermostat indicated a need for heat. This delay is essential in order that the oil, which has been withdrawn from the upper portion of the tube 44 will be heated in chamber 25 so that the first oil supply at tip 24 will be at the proper temperature for satisfactory atomization and ignition. Before the flow of oil can be obtained, however, the pressure control device of the present invention must complete its cycle of operation.

The control device is caused to function soon as the motor 22 cuts in and starts the operation of the pump 20 to pump oil into line 32 and through port 66. Normally during such periods as the motor is idle the piston 52 is disposed to the right-hand end of cylinder 50, as viewed in Figures 2 and 3. The first action of the pump in starting is to build up pressure in the cylinder 56, which pressure drives the piston 52 to the left until port E8 is uncovered. During travel of the piston to the left and before port 68 is uncovered or opened, the oil in the cylinder ahead of the piston is vented from the cylinder through passageway 52, past check valve 53. At the uncovering of port 58 oil will then flow under pressure through the tube 44 and be caused to circulate through the heat coil 3:) and finally to be discharged from the burner tip or nozzle 24 into the electrical discharge from the electrodes 38. This discharge of oil is preferably a continuous one so that there will be no pulsation in the flame due to any tendency for it to fail to remain burning.

As soon as pump 20 ceases to supply fuel under pressure to cylinder 59 the pressure immediately begins to drop in cylinder 50 owing to the bypass arrangement 84. A slight decrease in pres sure allows spring 54 to immediately retract piston 52 so that port 68 is sealed with, normally, full pressure on the oil in line 44. As piston 52 continues to move to the right as viewed in Figures 2 and 3, oil behind the piston vents out of the cylinder through the by-pass 3 3 and the piston creates a vacuum effect in the left-hand end of the cylinder inasmuch as port ii is also closed by the movement of piston 52 and ball check i3 is so seated as to prevent any suction through it. As soon as piston 52 has moved sufficiently far to the right as viewed, port 68 is again uncovered and the vacuum drawn gives a very quick suction effect on pipe i l, thus withdrawing quickly the oil in the burner end of tube 54. It will be apparent it is believed from the portion illustrated, that a piston 52 moves to the right the oil will be withdrawn for quite a degree in pipe 44 so that full assurance will be given that there will be none whatever left in upwardly slanting portion of pipe M. This prevents drip at the burner tip when the unit is shut down and by withdrawing the oil into the coil Bil the oil will be retained at its desirable operating temperature or, if the plant is shut down for an extended period, the oil will be again heated and properly conditioned before it is forced up into the nozzle portion of pipe l l.

By-pass 64 serves in addition to the purpose described three other functions; it provides a permanent air vent for the oil pump 2%; it eliminates the possibility of any oil or lower viscosity and flash point from entering the heater due to accidental delivery, as when an oil delivery company may have delivered the wrong type; therefore, eliminates the possible danger due to such a mistake, as pump 26 will by-pass oil if the cross-section of the by-pass such that pump 25] can discharge its total capacity of a lower viscosity oil through it without buildin" up sufficient pressure on piston 52 to open ti discharge port 68. A reversal of flow the fuel oil when the plant shuts down has a self-cleaning effect on both the nozzle screen 86 and the cylinder screen 'lil which has been found to be of real value in the successful operation of a plant of this order.

Chamber 28 may be supplied with water from any suitable source; a very convenient arrangement is to supply water from the normal pressure source through pipe 82. In this manner the cylinder will at all times be filled with water. Pro vided at the time of the initial filling, plug 811- is removed until water appears at this point. This will dispel all of the air from chamber 26 after which time the normal water pressure will keep the tank filled, and any pressure due to expansion will back up in the water in the supply pipe. Where water pressure is not available the chamber may be filled from an expansion tank located above the unit.

The foregoing description and the accompanying drawings are believed to clearly disclose a preferred embodiment of our invention but it will be understood that this disclosure is merely illustrative and that such changes in the invention may be made as are fairly within the scope and spirit of the following claims.

We claim:

1. A control device for burner nozzles comprising a cylinder closed to the atmosphere and having an inlet port and an outlet port spaced apart axially of said cylinder, a piston-valve in said cylinder between said inlet and outlet ports and adapted to move past and open the outlet port upon the introduction of fluid fuel under pressure to said cylinder, a spring operable to move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and re-position said piston-valve between the inlet and outlet ports upon the discontinuance of the inward flow of fluid fuel under pressure to thereby cause said piston-valve to withdraw fluid from said outlet port, and means for discharging from said cylinder the fluid fuel displaced by the repositioning of the piston valve.

2. A control device for burner nozzles comprising a cylinder having an inlet port and an outlet port spaced apart axially of said cylinder, a piston-valve in said cylinder between said inlet and outlet ports and adapted to open the outlet port upon the introduction of fluid fuel under pressure to said cylinder, a spring operable to re-position said piston-valve between the ilet and outlet ports upon the discontinuance of the inward flow of fluid fuel under pressure to thereby cause said piston-valve to withdraw fluid from said oulet port, and a relief outlet port in the inlet end of said cylinder for discharging from said cylinder the fluid fuel displaced by the repositioning of the piston-valve.

3. A control device for burner nozzles comprising a cylinder closed to the atmosphere and having an inlet port and an elongated outlet port, said inlet and outlet ports being longitudinally spaced-apart in the wall of the cylinder, an elongated piston-valve normally located in said cylinder between said inlet and outlet ports and adapted to move by and open the outlet port upon the introduction of fluid fuel under presto said cylinder, a spring operable to move the pistcn-valve past the outlet port in an opposite direction to uncover the outlet port and re-position said piston-valve between the inlet and outlet ports upon the discontinuance of the inward flow of fluid fuel pressure, and means for discharging from said cylinder the fluid fuel displaced by the re-positioning of the piston valve.

4. A control. device for burner nozzles comprising a cylinder closed to the atmosphere and having an inlet port and an outlet port spaced apart axially of said cylinder, a piston-valve in said cylinder between said inlet and outlet ports and adapted to move past and open the outlet port upon the introduction of fluid fuel under pressure to said cylinder, a contraction spring anchored to said piston-valve and to said cylinder and operable to move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and re-position said piston-valve between the inlet and outlet ports upon the di continuance of the inward flow of fluid fuel under pressure to thereby cause said piston-valve to withdraw fluid from said outlet port, and means for discharging from said cylinder the fluid fuel displaced by the re-positioning of the piston-valve.

5. A control device for oil burners comprising a cylinder closed to the atmosphere and having a fuel inlet port and a fuel outlet port spaced apart axially of said cylinder, a piston-valve in said cylinder which in the inactive position thereof lies between said ports but which under the influence of fuel pressure admitted into said inlet port is adapted to move axially toward and past said outlet port and open it for flow of fuel therethrough, and resilient means cooperable with said piston-valve to resist such movement toward and past said outlet port and upon termination of said fuel pressure move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and return said pistonvalve to said inactive position to thereby cause said piston-valve to withdraw fuel from said outlet port.

6. A control device for oil burners comprising a cylinder closed to the atmosphere and having a fuel inlet port and a fuel outlet port spaced apart axially of said cylinder, a piston-valve in said cylinder which in the inactive position thereof lies between said ports but which under the influence of fuel pressure admitted into said inlet port is adapted to move axially toward and past said outlet port and open it for fiow of fuel therethrough, resilient means cooperable with said piston-valve to resist such movement toward and past said outlet port and upon termination of said fuel pressure move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and return said piston-valve to said inactive position to thereby cause said pistonvalve to withdraw fuel from said outlet port, and fluid vent means ahead of said piston-valve to vent fluid from said cylinder as said pistonvalve moves toward aid outlet port.

7. A control device for oil burners comprising a cylinder closed to the atmosphere and having a fuel inlet port and a fuel outlet port spaced apart axially of said cylinder, a piston-valve in said cylinder which in the inactive position 7 thereof lies between said ports but which under the influence of fuel pressure admitted into said inlet port is adapted to move axially toward and past said outlet port and open it for flow of fuel therethrough, resilient means cooperable with said piston-valve to resist such movement toward and past said outlet port and upon termination of said fuel pressure move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and return said pistonvalve to said inactive position to thereby cause said piston-valve to withdraw fuel from said outlet port, and fluid vent means behind said pistonvalve to vent fluid from said cylinder as said piston-valve is returned to said inactive position by said resilient means.

8. A control device for oil burners comprising a cylinder closed to the atmosphere and having a fuel inlet port and a fuel outlet port spaced apart axially of said cylinder, a piston-valve in said cylinder which in the inactive position thereof lies between said ports but which under the influence of fuel pressure admitted into said inlet port is adapted to move axially toward and past said outlet port and open it for flow of fuel therethrough, resilient means cooperable with said piston-valve to resist such movement toward and past said outlet port and upon termination of said fuel pressure move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and return said pistonvalve to said inactive position to thereby cause said piston-valve to withdraw fuel from said outlet port, fluid vent means ahead of said pistonvalve to vent fluid from said cylinder as said piston-valve moves toward said outlet port, and fluid vent means behind said piston-valve to vent fluid from said cylinder as said piston-valve is returned to said inactive position by said resilient means.

9. A control device for oil burners comprising a cylinder closed to the atmosphere and having a fuel inlet port and a fuel outlet port spaced apart axially of said cylinder, said device also having a return port for returning fuel to a source, a piston-valve in said cylinder which in the inactive position thereof lies between the inlet and outlet ports, but which under the influence of fuel pressure admitted into said inlet port is adapted to move axially toward and past said outlet port to open it for flow of fuel therethrough, resilient means cooperable with said piston-valve to resist such movement toward and past said outlet port and upon termination of fuel pressure move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and return the piston-valve to its inactive position to thereby cause the piston-valve to withdraw fuel from the outl t port, and a passage for establishing communication between the inlet part of the cylinder and the return port.

10. A control device for oil burners comprising a cylinder closed to the atmosphere and having a fuel inlet port and a fuel outlet port spaced apart axially of said cylinder, said device also having a return port for returning fuel to a source, a piston-valve in said cylinder which in the inactive position thereof lies between the inlet and outlet ports, but which under the influence of fuel pressure admitted into said inlet port is adapted to move axially toward and past said outlet port to open it for flow of fuel therethrough, resilient means cooperaole with said piston-valve to resist such movement toward and past said outlet port and upon termination of fuel pressure move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and return the piston-valve to its inactive position to thereby cause the piston-valve to withdraw fuel from the outlet port, and a passage for establishing communication between the outlet part of the cylinder and the return port.

11. A control device for oil burners comprising a cylinder closed to the atmosphere and having a fuel inlet port and a fuel outlet port spaced apart axially of said cylinder, said device also having a return port for returning fuel to a source, a piston-valve in said cylinder which in the inactive position thereof lies between the inlet and outlet ports, but which under the influence of fuel pressure admitted into said inlet port is adapted to move axially toward and past said outlet port to open it for flow of fuel therethrough, resilient means cooperablo with said piston-valve to resist such movement toward and past said outlet port and upon termination of fuel pressure move the piston-valve past the outlet port in an opposite direction to uncover the outlet port and return the piston-valve to its inactive position to thereby cause the piston-valve to withdraw fuel from the outlet port, a passage for establishing communication between the inlet part of the cylinder and the return port, and another passage for establishing communication between the outlet part of th cylinder and the return port.

OSCAR C. TAPER. JOHN G. FROST. 

